export default function dropDialog(el){
    // 弹框可拉伸最小宽高
    const minWidth = 820
    // eslint-disable-next-line no-unused-vars
    const minHeight = 460
    // 初始非全屏
    let isFullScreen = false
    // 当前宽高
    let nowWidth = 0
    // eslint-disable-next-line no-unused-vars
    let nowHeight = 0
    // 当前顶部高度
    let nowMarginTop = 0
    // 获取弹框头部（这部分可双击全屏）
    const dialogHeaderEl = el.querySelector('.el-dialog__header')
    // 弹窗
    const dragDom = el.querySelector('.el-dialog')
    // 给弹窗加上overflow auto；不然缩小时框内的标签可能超出dialog；
    dragDom.style.overflow = 'auto'
    // 清除选择头部文字效果
    // dialogHeaderEl.onselectstart = new Function("return false");
    // 头部加上可拖动cursor
    dialogHeaderEl.style.cursor = 'move'
    // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
    const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null)
    const moveDown = (e) => {
        // 鼠标按下，计算当前元素距离可视区的距离
        const disX = e.clientX - dialogHeaderEl.offsetLeft
        const disY = e.clientY - dialogHeaderEl.offsetTop
        // 获取到的值带px 正则匹配替换
        let styL, styT
        // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
        if (sty.left.includes('%')) {
            styL = +document.body.clientWidth * (+sty.left.replace(/%/g, '') / 100)
            styT = +document.body.clientHeight * (+sty.top.replace(/%/g, '') / 100)
        } else {
            styL = +sty.left.replace(/px/g, '')
            styT = +sty.top.replace(/px/g, '')
        }
        document.onmousemove = function (e) {
            // 通过事件委托，计算移动的距离
            const l = e.clientX - disX
            const t = e.clientY - disY
            // 移动当前元素
            dragDom.style.left = `${l + styL}px`
            dragDom.style.top = `${t + styT}px`
            // 将此时的位置传出去
            // binding.value({ x: e.pageX, y: e.pageY })
        }
        document.onmouseup = function (e) {
            document.onmousemove = null
            document.onmouseup = null
        }
    }
    dialogHeaderEl.onmousedown = moveDown
    // 双击头部全屏效果
    dialogHeaderEl.ondblclick = (e) => {
        if (isFullScreen === false) {
            nowHeight = dragDom.clientHeight
            nowWidth = dragDom.clientWidth
            nowMarginTop = dragDom.style.marginTop
            dragDom.style.left = 0
            dragDom.style.top = 0
            dragDom.style.height = '100VH'
            dragDom.style.width = '100VW'
            dragDom.style.marginTop = 0
            isFullScreen = true
            dialogHeaderEl.style.cursor = 'initial'
            dialogHeaderEl.onmousedown = null
        } else {
            dragDom.style.height = 'auto'
            dragDom.style.width = nowWidth + 'px'
            dragDom.style.marginTop = nowMarginTop
            isFullScreen = false
            dialogHeaderEl.style.cursor = 'move'
            dialogHeaderEl.onmousedown = moveDown
        }
    }
    dragDom.onmousemove = function (e) {
        // eslint-disable-next-line no-unused-vars
        const moveE = e
        if (e.clientX > dragDom.offsetLeft + dragDom.clientWidth - 10 || dragDom.offsetLeft + 10 > e.clientX) {
            dragDom.style.cursor = 'w-resize'
            // eslint-disable-next-line brace-style
        }
        else if (el.scrollTop + e.clientY > dragDom.offsetTop + dragDom.clientHeight - 10) {
            dragDom.style.cursor = 's-resize'
        } else {
            dragDom.style.cursor = 'default'
            dragDom.onmousedown = null
        }
        dragDom.onmousedown = (e) => {
            const clientX = e.clientX
            const clientY = e.clientY
            const elW = dragDom.clientWidth
            // eslint-disable-next-line no-unused-vars
            const elH = dragDom.clientHeight
            const EloffsetLeft = dragDom.offsetLeft
            const EloffsetTop = dragDom.offsetTop
            dragDom.style.userSelect = 'none'
            // eslint-disable-next-line no-unused-vars
            const ELscrollTop = el.scrollTop
            // 判断点击的位置是不是为头部
            if (clientX > EloffsetLeft && clientX < EloffsetLeft + elW && clientY > EloffsetTop && clientY < EloffsetTop + 100) {
                // 如果是头部在此就不做任何动作，以上有绑定dialogHeaderEl.onmousedown = moveDown;
            } else {
                document.onmousemove = function (e) {
                    e.preventDefault() // 移动时禁用默认事件
                    // 左侧鼠标拖拽位置
                    if (clientX > EloffsetLeft && clientX < EloffsetLeft + 10) {
                        // 往左拖拽
                        if (clientX > e.clientX) {
                            dragDom.style.width = elW + (clientX - e.clientX) * 2 + 'px'
                        }
                        // 往右拖拽
                        if (clientX < e.clientX) {
                            if (dragDom.clientWidth < minWidth) {
                            } else {
                                dragDom.style.width = elW - (e.clientX - clientX) * 2 + 'px'
                            }
                        }
                    }
                    // 右侧鼠标拖拽位置
                    if (clientX > EloffsetLeft + elW - 10 && clientX < EloffsetLeft + elW) {
                        // 往左拖拽
                        if (clientX > e.clientX) {
                            if (dragDom.clientWidth < minWidth) {
                            } else {
                                dragDom.style.width = elW - (clientX - e.clientX) * 2 + 'px'
                            }
                        }
                        // 往右拖拽
                        if (clientX < e.clientX) {
                            dragDom.style.width = elW + (e.clientX - clientX) * 2 + 'px'
                        }
                    }
                    // 底部鼠标拖拽位置
                    if (ELscrollTop + clientY > EloffsetTop + elH - 20 && ELscrollTop + clientY < EloffsetTop + elH) {
                        // 往上拖拽
                        if (clientY > e.clientY) {
                            if (dragDom.clientHeight < minHeight) {
                            } else {
                                dragDom.style.height = elH - (clientY - e.clientY) * 2 + 'px'
                            }
                        }
                        // 往下拖拽
                        if (clientY < e.clientY) {
                            dragDom.style.height = elH + (e.clientY - clientY) * 2 + 'px'
                        }
                    }
                }
                // 拉伸结束
                document.onmouseup = function (e) {
                    document.onmousemove = null
                    document.onmouseup = null
                }
            }
        }
    }
    }
    
    